1. Field of the Invention
The present invention relates to a manufacturing method for a laminated ceramic electronic component such as a laminated inductor, and more particularly, the present invention relates to a manufacturing method for the laminated ceramic electronic component including a step of laminating a ceramic green sheet and a conductor supported by a carrier film using a transferring method.
2. Description of the Related Art
A laminated inductor using a sintered body that is obtained by integrally firing metals and ceramics is known. When the laminated inductor is manufactured, first, an internal electrode paste defining a coil conductor is printed on a ceramic green sheet. Then, a through-hole for electrically connecting the upper and lower internal electrodes is formed in the ceramic green sheet. A plurality of such green sheets is laminated and a laminate obtained in this way is pressed in the thickness direction. Next, by firing the laminate, a sintered ceramic body is obtained and a pair of external electrodes to be electrically connected to the coil conductor are formed on the external surface of the sintered ceramic body.
In the above laminated inductor, the number of turns is increased by increasing the number of laminated ceramic green sheets, and thus increased inductance is obtained.
However, in a method of printing an internal electrode paste defining a coil conductor on a ceramic green sheet, when the number of laminated ceramic green sheets increases, the difference in height between the portion where the internal electrode pastes exist and the portion where no internal electrode paste exists in the laminate increases. Because of this, when the laminate is pressed before firing, distortion occurs. Furthermore, because of the distortion, delamination between layers occurs after firing.
On the other hand, in the above-described laminated inductor, it is necessary to increase the thickness of the coil conductor or to increase the width of the coil conductor to reduce the direct-current resistance. However, in a method of forming internal electrodes, such as coil conductors, by printing an internal electrode paste on a ceramic green sheet, it is difficult to form a thick internal electrode in a single printing step.
Furthermore, even if a thick internal electrode is formed by repeating the printing of an internal electrode paste a plurality of times, when the laminate is pressed in the thickness direction, the above-mentioned distortion caused by pressure increases, and accordingly delamination between layers is more likely to occur in the obtained sintered ceramic body.
Furthermore, when the direct-current resistance is reduced by increasing the width of the coil conductor, the inductance becomes reduced.
The above-mentioned problems occur not only in laminated inductors, but also in laminated ceramic electronic components such as laminated ceramic capacitors. That is, when the number of laminated internal electrodes is increased, the distortion caused by pressure in the thickness direction increases as mentioned above, and delamination often occurs. Furthermore, when the thickness of an internal electrode is increased to lower the direct-current resistance, the above-mentioned delamination is much more likely to occur.
To overcome the above-described problems with the prior art, preferred embodiments of the present invention provide a manufacturing method for a laminated ceramic electronic component in which the thickness of an internal electrode is easily increased and, even if the number of laminated internal electrodes is increased, delamination does not occur.
Preferred embodiments of the present invention provide a manufacturing method for a laminated ceramic electronic component in which the thickness of a coil conductor as an internal electrode is easily increased and, even if the number of laminated internal electrodes is increased, delamination does not occur, and further, a greatly increased inductance is obtained.
According to a preferred embodiment of the present invention, a manufacturing method for a laminated ceramic electronic component, in which a laminate is obtained by laminating ceramic green sheets printed on a carrier film by a transferring method, a sintered body is obtained by firing the laminate, and external electrodes are formed on the external surface of the sintered body, includes the steps of printing the conductor and the ceramic green sheet provided around the conductor a plurality of times on the carrier film such that the conductors are provided one on top of another and the ceramic green sheets are provided one on top of another, thus forming a composite sheet laminate in which a plurality of composite sheets are laminated, each of the composite sheets including the conductor and the ceramic green sheet, and transferring the composite sheet laminate supported by the carrier film onto another ceramic green sheet by pressing and attaching the composite sheet laminate to the another ceramic green sheet and by removing the carrier film.
According to another preferred embodiment of the present invention, a manufacturing method for a laminated ceramic electronic component includes the steps of printing a conductor and a ceramic green sheet provided around the conductor a plurality of times on a first carrier film such that the conductors are provided one on top of another and the ceramic green sheets are provided one on top of another, thus forming a composite sheet laminate in which a plurality of composite sheets, each of which includes the conductor and the ceramic green sheet, are laminated, preparing a plurality of ceramic green sheet supports in which the ceramic green sheet is supported by a second carrier film, transferring the ceramic green sheets in the ceramic green sheet supports onto a laminating stage and removing the second carrier film, transferring at least one composite laminate by pressing and attaching the composite sheet laminate supported by the first carrier film to the ceramic green sheets on the laminating stage and by removing the first carrier film, pressing and attaching the ceramic green sheets in the ceramic green sheet supports to the composite sheet laminate transferred from the first carrier film and removing the second carrier film to obtain a laminate, firing the laminate to obtain a sintered ceramic body, and forming a plurality of external electrodes on the external surface of the sintered ceramic body.
Preferably, in the step of transferring the composite sheet laminate, the transferring of the composite sheet laminates is performed a plurality of times such that the conductors of the upper and lower composite sheet laminates are electrically connected.
Preferably, the conductors of the plurality of composite sheet laminates are constructed to form a coil inside the sintered ceramic body.
A manufacturing method for a laminated ceramic electronic component according to another preferred embodiment further includes the steps of forming connection electrode sheets including a connection electrode and a ceramic green sheet provided around the connection electrode, wherein when the plurality of composite sheet laminates are transferred, a plurality of the connection electrode sheets are transferred in the process of transferring a plurality of composite sheet laminates such that the conductors of the upper and lower composite sheet laminates are electrically connected by the connection electrode.
Preferably, the shape of the conductor in at least one of the composite sheet laminates is different from the shape of the conductors of the other composite sheet laminates.
It is also preferred that the transferring of the ceramic green sheet supported by a second carrier film is performed a plurality of times.
Preferably, when a ceramic green sheet is printed on the second carrier film to prepare the ceramic green sheet support, a plurality of the ceramic green sheet layers are printed.